#define _CRT_SECURE_NO_WARNINGS 1
class Solution {
public:
    bool isPalindrome(string s) {
        if (s.size() == 0) return true;


        string str = "";
        for (int i = 0; i < s.size(); i++)
        {
            if (isalnum(s[i]))
            {
                if (isupper(s[i]))  s[i] = tolower(s[i]);
                str += s[i];
            }
        }
        cout << str;

        for (int i = 0, j = str.size() - 1; i < j; i++, j--)
        {
            if (str[i] != str[j])  return false;
        }
        return true;
    }
};
